Many video graphics systems utilize user interface elements that enable a user to interface, in some way, with the video graphics and/or the application or system that renders the graphics. User interface elements can come in many types, geometries and sizes, such as boxes, buttons, sliders, knobs and the like which enable a user to provide input into the system. Alternately or additionally, user interface elements can be used to simply convey information to a user.
Regardless of the nature of the user interface elements, when a user interface is constructed by compositing video content and the user interface elements, as by layering one on top of the other, visually-perceptible problems can arise when the composition is ultimately rendered on a display, such as a television, for a user.
As an example, consider the following. User interface elements can contain sharp transitions or edges which, when passed through certain interpolators during compositing, such as up-samplers and follow-on filters as one might find in television encoding devices, can produce objectionable ringing on a television monitor. Ringing can manifest itself as fringing (in close up view) or as lack of sharpness (at a distance).
Accordingly, this invention arose out of concerns associated with providing systems and methods that can reduce this objectionable ringing while, at the same time preserve to a desirable degree the fidelity of the video content.